1. Field of the Invention
The present invention relates to a disc chucking apparatus for chucking or clamping a disc such as a video disc, an audio disc, or the like, and loading the chucked disc into a recording and/or reproducing system.
2. Description of the Prior Art
Reproducing systems for video discs, audio discs, or the like, particularly those known as "karaoke" systems for playing back orchestral or instrumental accompaniments, comprise an automatic disc changer for storing a number of discs, taking out a desired one of the stored discs, and loading the disc into a reproducing mechanism.
One such automatic disc changer has a disc chucking apparatus including a pair of clamp members movable radially inwardly toward the disc for gripping the outer circumferential edge of the disc, and a disc support disposed inwardly of the lower ends of the clamp members for chucking or clamping thereon the disc chucked by the check members.
The disc chucking apparatus of another automatic disc changer comprises a chuck which has an insert member insertable into the central hole of a disc and an abutment support which will abut against the peripheral edge of the disc that defines the central hole thereof. The chuck also includes a presser attached to an upper circumferential surface of the insert member and extending parallel to the abutment support. In operation, the insert member is inserted in the central hole of the disc, and the abutment support is held against the peripheral edge of the central hole. Then, the presser is spread to grip the peripheral edge of the disc between the abutment support and the presser itself, thereby chucking the disc in place.
In the former disc chucking apparatus, since the disc is gripped at its outer circumferential edge, disc trays for housing and storing discs are required to have recesses for receiving the clamp members. Therefore, the discs stored in the disc trays may possibly be warped or otherwise distorted as the circumferential edges thereof are not firmly retained in their entirety. In addition, the disc trays are relatively complex in structure. Inasmuch as the clamp members are positioned radially outwardly of the discs, the disc chucking apparatus is large in size, and hence the automatic disc changer which incorporates the disc chucking apparatus is large in size and also expensive to manufacture.
The latter disc chucking apparatus is relatively small in size because the chuck clamps discs at their central holes. The insert member is inserted into the central hole of the disc from the lower side thereof, and the presser is pressed against the disc from the upper side thereof. If the insert member were inserted into the central hole from the upper side of the disc to chuck the same, the disc would be forcibly pressed against a disc tray on which the disc is supported, with the result that the recording surface of the disc would tend to be damaged. It is therefore not desirable to chuck the disc from the upper side thereof. Particularly, it is impossible to chuck the disc from a position that is relatively spaced from the upper side of the disc.